Electric-arc lamp.



No. 662,995. Patented Dec. 4, I900.-

0. u. WISWELL. ELECTRIC ARC LAMP.

[Application filed May 4, 1899.:

(No Model.)

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NITED STATES PATENT FFICE.

OZRO NEWCOME WISWVELL, OF LYNN, MASSACHUSETTS, ASSIGNOR TO THE GENERAL ELECTRIC COMPANY, OF NEIV YORK.

ELEOTRlC-ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 662,995, dated. December 4, 1900.

Application filed May 4,1899- Serial No. 715,508. (No model.)

Z all whom it may concern.- The poles are connected at the bottom by a Be it known that I, OZRO NEWCOME NIS- yoke D and at the top by a non-magnetic WELL, a citizen ofthe United States, residing clamp E. Situated just above the clamp 011 at Lynn, in the county of Essex and State of each pole-piece is a detachable ring F, made ldassachnsetts,have invented certain new and of iron or steel, as desired, which ring may or usefulImprovements in Arc-Lamps, of which may not be split. It is preferable to make the following is a specification. the ring out of steel on account of the addi- In electric-arc lamps of certain well-known tional elasticity. types it has long been thought necessary to The cores G are commonly made from 60 1'0 arrange the magnetsin such manner that they wrought iron or steel rods, and for that reawould give a constant pull over a wide range son it is preferable to employ rings which can of movement. To attain this end,pole-pieces be slipped over the pole-tips rather than to having paraboloidal tips have been used in cut the cores with a projection out of solid connectionwith armatures having holestherestock, as it would involve a good deal of la- G in for the reception of the pole-tips. bor, besides costing more for material. The In double-carbon lamps of the above types rings can readily be made in a machine and the voltage across the arc of the second pair can be applied to the lamp without disturbof carbons is always higher than the voltage ing any portion of the lamp mechanism. across the are of the first pair of carbons. The armature C is pivoted at any suitable 7o This is due chiefly to the fact that the load on point, and an adj usting-sprin g H is employed the adjusting-spring or its equivalent is deto return it to the position shown. This arcreased by an amount corresponding to the mature controls the action of the carbon-rods weight of the carbon consumed on the first I and I through suitable clutches. WVhen rod, and consequently the carbons are slightly the carbon carried by rod I is consumed, the 75 more separated than in the first instance. second rod, with its carbon, is brought into I have discovered that it is not advisable in action by suitable mechanism. (Not shown.) thetypesoflamp above referred to to make the The carbon-rod I feeds when the armature magnets exert a constant pull on their armamoves downward to a point about five-sixt'ures over their entire range, but instead that teenths of an inch from the clamp E, and the 8o they should exert a sharp increase in pull at rod I feeds when the armature moves to a or about the clutch-tripping point. By placpoint about one-fourth of an inch from the ing a small ring of steel or iron, preferably clamp. the former, around the base of the parabo- At the present time there is a large numloidal tip Iam enabled to operate a Thomsonber of these lamps in daily operation, and I 85 Houston double-carbon lamp in such manner can utilize my invention in connection with that the voltage of both rods is practically these lamps by providing a pair of springidentical. This is an important feature when rings for each lam p, which rings can be sprung the addition of several volts for each lamp over the pole-tip and will remain, due to their supplied from a station is taken into considgripping action. I have found by actual test 0 4o oration, and, further, the saving in operation that closer regulation of both carbons can be usually comes after midnight, when the addiobtained with my invention than without and tional light is unnecessary. that the second carbon will burn at the same Referring to the accompanying drawings, voltage as the first with no rise in voltage. which show an embodiment of my invention, Having thus described my invention, what 95 5 Figure 1 is a front elevation of a lamp, and I claim, and desire to secure by Letters Pat- Fig. 2 is a perspective view of a ring. out, is-

In the drawings, A and B represent elec- 1. In an electric-arc lamp, the combination tromay'nets having cores G with araboloidal of a feed-regulatirw ma net rovided with a "a a. p o a pole-tips G, and mounted for movement with core and armature, one of which is perma- I00 respectthereto is an armature C, havingholes nently fixed and the other movable, the two therein through which the pole-tips can pass. having cooperating faces shaped to produce a sudden decrease of the magnetic reluctance of the circuit and thereby afford a sharp increase of pull at or near the feeding-point of the lamp.

2. In an electric-arc lamp, the combination of a feed-regulating magnet having a paraboloidal pole-tip, and an armature surrounding the pole-tip, the pole-tip beingprovided with an enlargement of magnetic material at or near the feeding'point for exerting a sharp increase of pull.

3. In an electric-arc lamp, the combination of a core having a paraboloidal pole-tip, a Winding therefor, an armature containing a hole for the reception of the pole-piece, and

In Witness whereof I have hereunto set my 25 hand this 26th day of April, 1899.

OZRO NEWCOME WISWELL. Vitnesses:

ALEX F. MACDONALD, D'UeALn MGKILLOP. 

